From all experience Admiralty consider project of attempting to close exit to North Sea to enemy submarines by method suggested to be quite impracticable. Project has previously been considered and abandoned. The difficulty will be appreciated when total distance, depths material and patrols required and distance from base of operations are considered. Even were it practicable to lay, maintain and protect such a barrage it would not owing to want of resilience prove effective against the passage of submarines fitted with cutters. . . .

Source Note: Cy, UK-KeNA, Admiralty 137/655. In the left margin is stamped: “COPIED.”

Footnote 1: It is likely that the author of this telegram was RAdm. Sir Alexander L. Duff, former Director of the Anti-Submarine Division of the Admiralty and then Assistant Chief of Naval Staff.

Footnote 2: Commo. Guy R. Gaunt, British Naval Attaché at Washington. Gaunt was to deliver the message to de Chair.

Footnote 3: Earlier the same day, de Chair had forwarded an American proposal to create a North Sea mine barrage asking if Admiralty officials considered it “possible.”

Footnote 4: de Chair was part of a naval mission to the United States.